I can use modeprobe option to bring up my 3g dongle but can't find a program like pon to bring a script up. (anyone have an answer?)
But enough about me. Please could someone make a gui for 3g so you can run it as your WAN.

I am having something similar in mind.
Is it possible to share internet connection from a USB dongle or USB devise like Alfa AWUS036H?
Technically internet connection will be received from the USB port insted of RJ45 and then repeat the same…

The ideal setup would be to have the main ISP connected on WAN port by UTP cable, and a 3G USB dongle as a back up WAN connection, configured for fail over. Hope to have this dream come true one day. :)

Indeed, such a failover option (If WAN Ethernet fails, use 3G) would be great. On the other hand I'd be happy to just see the ability to manually switch between the two using the GUI, and in some ways I'd prefer this, reason being I'm usually torrenting 24/7, and if the ADSL goes down, I wouldn't want to be torrenting over 3G for hours without knowing.

Since it's not possible to check if the WAN goes up, would it be possible to have a script that check if 3G is active and switch to WAN let's say after 2 hours, regardless of the WAN status? If the WAN is not up the 3G failover will start again and this process will repeat until the WAN is working.